1 files changed, 110 insertions, 0 deletions
diff --git a/modules/apps/cassandra/default.nix b/modules/apps/cassandra/default.nix
new file mode 100644
index 0000000..953acb3
--- /dev/null
+++ b/modules/apps/cassandra/default.nix
@@ -0,0 +1,110 @@
+{ config, lib, pkgs, ... }:
+
+let
+
+  inherit (builtins)
+    match ;
+
+  inherit (lib)
+    concatMapStringsSep concatStringsSep filterAttrs flatten foldAttrs foldl
+    mapAttrsToList mkOption ;
+
+  inherit (lib.types)
+    attrsOf submodule ;
+
+  explicit = filterAttrs (n: v: n != "_module" && v != null);
+  concatMapAttrsSep = s: f: attrs: concatStringsSep s (mapAttrsToList f attrs);
+
+  instances = explicit config.nixsap.apps.cassandra;
+  users = mapAttrsToList (_: i: i.user) instances;
+
+  keyrings =
+    let
+      ik = mapAttrsToList (n: i: { "${i.user}" = []; } ) instances;
+    in foldAttrs (l: r: l ++ r) [] ik;
+
+  mkService = name: cfg:
+    let
+
+      tmpdir = "${cfg.home}/tmp";
+      cp = concatStringsSep ":" cfg.classpath;
+
+      isDir = d: _: match ".*_director(y|ies)$" d != null;
+      directories = [ cfg.home ]
+        ++ flatten (mapAttrsToList (_: d: d) (filterAttrs isDir (explicit cfg.parameters)));
+
+      directories_sh = concatMapStringsSep " " (d: "'${d}'") directories;
+
+
+      start = pkgs.writeBashScriptBin "cassandra-${name}" ''
+        set -euo pipefail
+        umask 0027
+        export HOME='${cfg.home}'
+
+        rm   -rf -- '${cfg.jre.properties.java.io.tmpdir}'
+        mkdir -p -- '${cfg.jre.properties.java.io.tmpdir}'
+
+        exec ${cfg.jre.package}/bin/java \
+        -Dcassandra.config='${cfg.jre.properties.cassandra.config}' \
+        -Djava.io.tmpdir='${cfg.jre.properties.java.io.tmpdir}' \
+        -Djava.library.path='${concatStringsSep ":" cfg.jre.properties.java.library.path}' \
+        -cp '${cp}' \
+        org.apache.cassandra.service.CassandraDaemon
+
+      '';
+
+    in {
+      "cassandra-${name}" = {
+        description = "Cassandra (${name}) distributed NoSQL database";
+        wantedBy = [ "multi-user.target" ];
+        after = [ "keys.target" "network.target" "local-fs.target" ];
+        preStart = ''
+          mkdir -p -- ${directories_sh}
+
+          find ${directories_sh} -not -type l \( \
+              -not -user '${cfg.user}' \
+          -or -not -group '${cfg.user}' \
+          -or \( -type d -not -perm -u=wrx,g=rx \) \
+          -or \( -type f -not -perm -u=rw,g=r \) \
+          \) \
+          -exec chown -c -- '${cfg.user}:${cfg.user}' {} + \
+          -exec chmod -c -- u=rwX,g=rX,o= {} +
+
+        '';
+
+        unitConfig = {
+          # XXX It can be running long before fail:
+          StartLimitBurst = 3;
+          StartLimitIntervalSec = 60;
+        };
+
+        serviceConfig = {
+          ExecStart = "${start}/bin/cassandra-${name}";
+          KillMode = "mixed";
+          PermissionsStartOnly = true;
+          Restart = "always";
+          TimeoutSec = 0;
+          User = cfg.user;
+          LimitAS = "infinity";
+          LimitMEMLOCK = "infinity";
+          LimitNOFILE = 10000;
+          LimitNPROC = 32768;
+        };
+      };
+    };
+
+in {
+
+  options.nixsap.apps.cassandra = mkOption {
+    description = "Cassandra instances";
+    default = {};
+    type = attrsOf (submodule (import ./instance.nix pkgs));
+  };
+
+  config = {
+    systemd.services = foldl (a: b: a//b) {} (mapAttrsToList mkService instances);
+    nixsap.deployment.keyrings = keyrings;
+    nixsap.system.users.daemons = users;
+  };
+
+}